1-Bit Matrix Completion

In this paper we develop a theory of matrix completion for the extreme case of noisy 1-bit observations. Instead of observing a subset of the real-valued entries of a matrix M, we obtain a small number of binary (1-bit) measurements generated according to a probability distribution determined by the real-valued entries of M. The central question we ask is whether or not it is possible to obtain an accurate estimate of M from this data. In general this would seem impossible, but we show that the maximum likelihood estimate under a suitable constraint returns an accurate estimate of M when ||M||_{\infty} <= \alpha, and rank(M) <= r. If the log-likelihood is a concave function (e.g., the logistic or probit observation models), then we can obtain this maximum likelihood estimate by optimizing a convex program. In addition, we also show that if instead of recovering M we simply wish to obtain an estimate of the distribution generating the 1-bit measurements, then we can eliminate the requirement that ||M||_{\infty} <= \alpha. For both cases, we provide lower bounds showing that these estimates are near-optimal. We conclude with a suite of experiments that both verify the implications of our theorems as well as illustrate some of the practical applications of 1-bit matrix completion. In particular, we compare our program to standard matrix completion methods on movie rating data in which users submit ratings from 1 to 5. In order to use our program, we quantize this data to a single bit, but we allow the standard matrix completion program to have access to the original ratings (from 1 to 5). Surprisingly, the approach based on binary data performs significantly better

Higher Alpha/Theta Ratio May Indicate Decreased Brain Function in Older Adults during CSPFP10 Compared to Young Adults

Declined physical ability and brain function observed in elder can affect daily living activities and negatively influence the quality of life (QOL). While the extensive research has explored the changes in cortical activity related to motor control in elder, less is known about how the brain functions during a physical function test. PURPOSE: To examine the electrocortical activation in the older adults’ brain during the Continuous Scale Physical Function Performance-10 (CSPFP-10) compared to young adults. METHODS: Twenty five older adults (OLD; 75.40±7.32 yrs, 70.33±18.23 kg, 162.87±7.55 cm) and twenty five young (YOUNG; 19.88±1.72 yrs, 66.52±14.22 kg, 167.50±10.22 cm) completed CSPFP10 while frontal (F3, Fz, F4), central (C3, Cz, C4), temporal (T7, T8, P7, P8), parietal (P3, Pz P4), and occipital (O1, Oz, O2) regions’ electrocortical activation was measured using a mobile electroencephalograph (EEG). Spectral power values (μV2/Hz) for theta (θ: 4-8 Hz) and alpha (α: 8-13 Hz) band were averaged across the target electrodes. Then α/θ ratio was calculated. Data were analyzed using independent t-test. RESULTS: OLD exhibited significantly higher α/θ ratio in frontal (M=0.98 vs.0.95, pp=.02), temporal (M=1.02 vs. 0.98, p=.006) compared to YOUNG. The separated t-test showed YOUNG had higher θ and α in frontal (θ: M= 40.93 vs. 37.56, pp=.03), central (θ: M=39.68 vs. 36.43, pp=.038), and parietal θ (M=40.55 vs. 37.98, p=.001) compared to OLD. Pearson’s correlation analysis did not find any significance between brain function and CSPFP10 scores in both groups. CONCLUSION α/θ ratio in OLD showed that their α power was relatively higher than YOUNG. Increased α power indicates suppression/selective cortical processing. It might indicate that OLD had inhibitory cortical activation process during the CSPFP10 task. Decreased frontal and parietal θ in OLD may indicate diminished decision making speed and attention with aging, while lower θ power in a central region (motor cortex) implies disrupt motor control. Overall, our result may indicate that brain activation patterns become less active during aging. It’s important to enhance both physical and brain function to improve activities of daily living and QOL in elderly population

Construction and Nursing Students, Building a Playground for Bauer Family Services

Poster Sessio

Social Support and Smoking Abstinence among Incarcerated Adults in the United States: A Longitudinal Study

Background: In the United States, tobacco use among prisoners is nearly three times that of the general population. While many American prisons and jails are now tobacco-free, nearly all inmates return to smoking as soon as they are released back into the community. Methods: To better understand the role that personal relationships may play in enabling return to smoking, we enrolled former-smokers who were inmates in a tobacco-free prison. Baseline assessments were conducted six weeks prior to inmates’ scheduled release and included measures of smoking prior to incarceration, motivation, confidence and plans for remaining quit after release. We also assessed global social support (ISEL) and a measure of social support specific to quitting smoking (SSQ). Smoking status was assessed three weeks after prison release and included 7-day point-prevalence abstinence validated by urine cotinine, days to first cigarette and smoking rate. Results: A diverse sample comprised of 35% women, 20% Hispanic, and 29% racial minorities (average age 35.5 years) provided baseline data (n = 247). Over 90% of participants provided follow up data at 3-weeks post-release. Prior to incarceration participants had smoked an average of 21.5 (SD = 11.7) cigarettes per day. Only 29.2% had definite plans to remain smoking-abstinent after release. Approximately half of all participants reported that “most” or “all” of their family (42.2%) and friends (68%) smoked, and 58.8% reported their spouse or romantic partner smoked. SSQ scores were not significantly predictive of smoking outcomes at three weeks, however, social support from family and friends were each significantly and positively correlated with motivation, confidence, and plans for remaining abstinent (all p values Conclusions: Inmates of smoke-free prisons have a head-start on being smoke-free for life. They have been abstinent well past the duration of nicotine withdrawal and have great financial incentive not to begin smoking again. However, this advantage may be offset by a lack of non-smoking role models among their family and friends, and perceived lack of support for remaining smoke-free. Trial Registration: ClinicalTrials.gov Identifier: NCT0168499

Outbreak of Fatal Childhood Lead Poisoning Related to Artisanal Gold Mining in Northwestern Nigeria, 2010.

Background: In May 2010, a team of national and international organizations was assembled to investigate children's deaths due to lead poisoning in villages in northwestern Nigeria. Objectives: To determine the cause of the childhood lead poisoning outbreak, investigate risk factors for child mortality, and identify children aged <5 years in need of emergency chelation therapy for lead poisoning. Methods: We administered a cross-sectional, door-to-door questionnaire in two affected villages, collected blood from children aged 2-59 months, and soil samples from family compounds. Descriptive and bivariate analyses were performed with survey, blood-lead, and environmental data. Multivariate logistic regression techniques were used to determine risk factors for childhood mortality. Results: We surveyed 119 family compounds. One hundred eighteen of 463 (25%) children aged <5 years had died in the last year. We tested 59% (204/345) of children, aged <5 years, and all were lead poisoned (≥10 µg/dL); 97% (198/204) of children had blood-lead levels ≥45 µg/dL, the threshold for initiating chelation therapy. Gold ore was processed inside two-thirds of the family compounds surveyed. In multivariate modeling significant risk factors for death in the previous year from suspected lead poisoning included: the child's age, the mother performing ore-processing activities, community well as primary water source, and the soil-lead concentration in the compound. Conclusion: The high levels of environmental contamination, percentage of children aged <5 years with elevated blood-lead levels (97%, >45 µg/dL), and incidence of convulsions among children prior to death (82%) suggest that most of the recent childhood deaths in the two surveyed villages were caused by acute lead poisoning from gold ore-processing activities. Control measures included environmental remediation, chelation therapy, public health education, and control of mining activities

Research in the Work of New Zealand Teacher Educators: A CHAT Perspective

Accepted for publication version - Pre-proof and correctionsIn this article we use Cultural Historical Activity Theory (CHAT) to explore the place of research in the work of New Zealand university-based teacher educators (TEs). We consider how aspirations for a research-informed initial teacher education (ITE) are served by New Zealand universities’ recruitment practices and TE’s actual work. We suggest that TEs value scholarship that informs their practice and are motivated to research, despite working within institutions where employment practices are bifurcating the teacher educator (TE) workforce along lines of who can and should do research and who should not. We cite evidence from interviews to suggest TEs, and those in leadership positions who have been involved in TE recruitment, recognize the importance of research to inform practice and teaching. However, this conflicts with the language of advertisements and job descriptions where for some TE roles, the practice of research and scholarship are not an object of work. In response, we encourage those responsible for TE work force development to support and employ TEs able to engage in high standards of scholarship and teaching, and in so doing provide their students with research- and practice-informed teaching.Peer Reviewe

PCR-based genotyping of Helicobacter pylori of Gambian children and adults directly from biopsy specimens and bacterial cultures

<p>Abstract</p> <p>Background</p> <p><it>Helicobacter pylori </it>is an important agent of gastroduodenal disease in Africa and throughout the world. We sought to determine an optimum method for genotyping <it>H. pylori </it>strains from children and adults in The Gambia, West Africa.</p> <p>Results</p> <p>Virulence genes were amplified in 127 of 190 cases tested (121 adults and 6 children); each of 60 bacterial cultures, and 116 from DNA extracted directly from biopsies. The proportion of biopsies that were <it>cagA</it>+, the ratio of <it>vacAs1</it>/<it>s2</it>, and <it>vacAm1</it>/<it>m2</it>, and the proportion of mixed strain populations in individual subjects changed with age. Strains lacking virulence <it>cagA </it>and <it>vacA </it>genes and with apparently homogeneous (one predominant strain) infections were more common among infants than adults.</p> <p>Conclusions</p> <p>In order to detect the range of bacterial genotypes harbored by individual patients, direct PCR proved slightly superior to isolation of <it>H. pylori </it>by biopsy culture, but the techniques were complementary, and the combination of both culture and direct PCR produced the most complete picture. The seemingly higher virulence of strains from adult than infant infections in The Gambia merits further analysis.</p

Constructing the academic category of teacher educator in Aotearoa New Zealand university recruitment processes.

Accepted for publication version - Pre-proof and correctionsAn examination of recruitment materials and interviews with personnel involved in the employment of teacher educators to positions in university-based New Zealand initial teacher education reveals three constructions of teacher educator as academic worker: the professional expert, the dually qualified, and the traditional academic. However, our analysis shows how these constructions allow universities to pursue a bifurcated approach to the employment of teacher educators; an approach that maintains binaries within teacher education and hinders development in the field. Furthermore, as the spectre of a major cultural shift in the provision of New Zealand ITE arises, the extent to which the professional expert and traditional academic constructions of teacher educator might serve the scope of work required of post-graduate ITE going forth is questioned.Peer Reviewe

The association between impulsivity and alcohol/drug use among prison inmates

Background: Few studies have examined the relation between impulsivity and drug involvement with prison inmates, in spite of their heavy drug use. Among this small body of work, most studies look at clinically relevant drug dependence, rather than drug use specifically. Method: N = 242 adult inmates (34.8% female, 52% White) with an average age of 35.58 (SD = 9.19) completed a modified version of the 15-item Barratt Impulsiveness Scale (BIS) and measures assessing lifetime alcohol, opiate, benzodiazepine, cocaine, cannabis, hallucinogen, and polysubstance use. Lifetime users also reported the frequency of use for the 30 days prior to incarceration. Results: Impulsivity was higher among lifetime users (versus never users) of all substances other than cannabis. Thirty day drug use frequency was only related to impulsivity for opiates and alcohol. Discussion: This study extends prior work, by showing that a lifetime history of non-clinical substance use is positively associated with impulsivity among prison inmates. Implications for drug interventions are considered for this population, which is characterized by high rates of substance use and elevated impulsivity

Changes in Depression and Stress after Release from a Tobacco-Free Prison in the United States

Prior research has found high levels of depression and stress among persons who are incarcerated in the United States (U.S.). However, little is known about changes in depression and stress levels among inmates post-incarceration. The aim of this study was to examine changes in levels of depression and stress during and after incarceration in a tobacco-free facility. Questionnaires that included valid and reliable measures of depression and stress were completed by 208 male and female inmates approximately eight weeks before and three weeks after release from a northeastern U.S. prison. Although most inmates improved after prison, 30.8% had a worsening in levels of depression between baseline and the three-week follow-up. In addition, 29.8% had a worsening in levels of stress after release than during incarceration. While it is not surprising that the majority of inmates reported lower levels of depression and stress post-incarceration, a sizable minority had an increase in symptoms, suggesting that environmental stressors may be worse in the community than in prison for some inmates. Further research is needed to address depression and stress levels during and after incarceration in order for inmates to have a healthier transition back into the community and to prevent repeat incarcerations